b) 1/2023. -7/9+ 2022/2023. -7/9+7/9

b) 12023.−79+20222023.−79+79

=12023.−79+20222023.−79+−79.−1

=−79.12023+20222023−1

=−79.20232023−1=−79.1−1=−79.0=0